Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for HD 189733: 11-06 (95), 11-07 (94), 11-05 (93), 11-08 (93), 11-04 (92) — by astronomy; check the weather when the night is within four days.

2039-10-30astronomy score per night — click a bar for that night2039-11-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-10-30 Sun	50	—	unknown	18:55–20:55 (good, 2.0 h)	71.1° 17:50	10.42	99%	83.0°
2039-10-31 Mon	57	—	unknown	18:55–21:30 (good, 2.58 h)	71.1° 17:45	10.46	100%	91.5°
2039-11-01 Tue	66	—	unknown	18:50–22:10 (good, 3.33 h)	71.1° 17:40	10.5	99%	99.9°
2039-11-02 Wed	74	—	unknown	18:50–22:25 (good, 3.58 h)	71.1° 17:35	10.53	96%	107.9°
2039-11-03 Thu	89	—	unknown	18:50–22:25 (good, 3.58 h)	71.1° 17:30	10.57	92%	115.4°
2039-11-04 Fri	92	—	unknown	18:50–22:25 (good, 3.58 h)	71.1° 17:30	10.6	86%	122.1°
2039-11-05 Sat	93	—	unknown	18:50–22:25 (good, 3.58 h)	71.1° 17:25	10.64	79%	127.6°
2039-11-06 Sun	95	—	unknown	18:45–22:20 (good, 3.58 h)	71.1° 17:20	10.67	71%	131.5°
2039-11-07 Mon	94	—	unknown	18:45–22:20 (good, 3.58 h)	71.1° 17:15	10.71	62%	133.4°
2039-11-08 Tue	93	—	unknown	18:45–22:20 (good, 3.58 h)	71.1° 17:15	10.74	52%	133.0°
2039-11-09 Wed	92	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:10	10.77	42%	130.2°
2039-11-10 Thu	91	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:05	10.8	33%	125.3°
2039-11-11 Fri	89	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:00	10.83	23%	118.5°
2039-11-12 Sat	89	—	unknown	18:40–22:05 (good, 3.42 h)	71.1° 16:55	10.87	15%	110.3°
2039-11-13 Sun	87	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.9	8%	101.1°
2039-11-14 Mon	86	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:50	10.93	3%	91.2°
2039-11-15 Tue	84	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:45	10.95	0%	81.0°
2039-11-16 Wed	82	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:40	10.98	1%	71.0°
2039-11-17 Thu	80	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:35	11.01	4%	61.8°
2039-11-18 Fri	77	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:35	11.04	10%	54.1°
2039-11-19 Sat	70	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:30	11.06	19%	48.8°
2039-11-20 Sun	60	—	unknown	18:35–21:30 (good, 2.92 h)	71.1° 16:25	11.09	29%	46.5°
2039-11-21 Mon	50	—	unknown	18:35–21:15 (good, 2.67 h)	71.1° 16:20	11.12	39%	47.6°
2039-11-22 Tue	42	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 16:20	11.14	50%	51.5°
2039-11-23 Wed	36	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 16:15	11.16	61%	57.4°
2039-11-24 Thu	33	—	unknown	18:35–19:40 (good, 1.08 h)	71.1° 16:10	11.19	71%	64.6°
2039-11-25 Fri	31	—	unknown	18:35–19:25 (good, 0.83 h)	71.1° 16:05	11.21	80%	72.6°
2039-11-26 Sat	31	—	unknown	18:35–19:30 (good, 0.92 h)	71.1° 16:00	11.23	87%	80.9°
2039-11-27 Sun	33	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 16:00	11.25	93%	89.4°
2039-11-28 Mon	36	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:55	11.27	97%	97.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-10-30&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.